ypbind - NIS binding process
ypbind [ -c ] [ -d|-debug ] [ -v|-verbose ] [ -broadcast ] [ -broken-
server ] [ -ypset ] [ -ypsetme ] [ -no-ping ] [ -p port ] [ -f config-
file ] [ -local-only ] [ -ping-interval ping-interval ]
ypbind finds the server for NIS domains and maintains the NIS binding
information. The client (normaly the NIS routines in the standard C
library) could get the information over RPC from ypbind or read the
binding files. The binding files resides in the directory /var/yp/bind-
ing and are conventionally named [domainname].[version]. The supported
versions are 1 and 2. There could be several such files since it is
possible for an NIS client to be bound to more then one domain.
After a binding has been established, ypbind will send YPPROC_DOMAIN
requests to the current NIS server at 20 seconds intervals. If it
doesn't get an response or the NIS server reports that he doesn't have
this domain any longer, ypbind will search for a new NIS server. All 15
minutes ypbind will check to see if the current NIS server is the
fastest. If it find a server which answers faster, it will switch to
this server. You could tell ypbind to use network broadcasts to find a
new server, what is insecure, or you could give it a list of known
secure servers. In this case ypbind will send a ping to all servers
and binds to first one which answers.
Unless the option -debug is used, ypbind detaches itself from the con-
trolling terminal and puts itself into background. ypbind uses sys-
log(3) for logging errors and warnings. At startup or when receiving
signal SIGHUP, ypbind parses the file /etc/yp.conf and tries to use the
entries for its initial binding. Valid entries are
domain nisdomain server hostname
Use server hostname for the domain nisdomain. You could have
more then one entry of this type for a single domain.
domain nisdomain broadcast
Use broadcast on the local net for domain nisdomain.
Use server server for the local domain.
A broadcast entry in the configuration file will overwrite a
ypserver/server entry and a ypserver/server entry broadcast. If all
given server are down, ypbind will not switch to use broadcast. ypbind
will try at first /etc/hosts and then DNS for resolving the hosts names
from /etc/yp.conf. If ypbind couldn't reconfigure the search order, it
will use only DNS. If DNS isn't available, you could only use IP-
addresses in /etc/hosts. ypbind could only reconfigure the search
order with glibc 2.x. If the -broadcast option is specified, ypbind
will ignore the configuration file. If the file does not exist or if
there are no valid entries, ypbind exit.
This ypbind is a special version which uses pthreads. It will start 2
more threads. The master process services RPC requests asking for
binding info. The first thread initializes the binding and checks it
periodically. Upon failure, the binding is invalidated and the process
tries again to find a valid server. The second thread will handle all
Send a broadcast to request the information needed to bind to a
specific NIS server. With this option, /etc/yp.conf will be
-ypset Allow root from any remote machine to change the binding for a
domain via the ypset(8) command. By default, no one can change
the binding. This option is really insecure. If you change a
binding for a domain, all the current known servers for this
domain will be forgotten. If the new server goes down, ypbind
will use the old searchlist.
The same as -ypset, but only root on the local machine is
allowed to chang the binding. Such requests are only allowd from
-c ypbind only checks if the config file has syntax errors and
-debug starts ypbind in debug mode. ypbind will not put itself into
background, and error messages and debug output are written to
Causes ypbind to syslog(2) any and all changes in the server its
lets ypbind accept answers from servers running on an illegal
port number. This should usually be avoided, but is required by
some ypserv(8) versions.
ypbind will not check if the binding is alive. This option is
for use with dialup connections to prevent ypbind from keeping
the connection unnessecarily open or causing autodials.
ypbind will bind itself to this port. This makes it possible to
have a router filter packets to the NIS ports, so that access to
this service from hosts on the Internet can be restricted.
ypbind will use configfile and not /etc/yp.conf
ypbind will only bind to the loopback device and is not
reacheable from a remote network.
The default value for ypbind to check, if a NIS server is still
reacheable, is 20 seconds. With this options another frequency
in seconds can be specified.
Prints the version number
Binding to multiple domains is tested and works. Load sharing between
multiple servers for a single domain is not supported. ypbind will
always try to bind a domain to a server. If there is no valid server in
the list or answers to a broadcast, the domain is unbounded.
binding file containing information about each NIS domain.
contains the process id of the currently running ypbind master
syslog(3), domainname(1), ypdomainname(8), ypwhich(1), ypserv(8),
ypbind-mt was written by Thorsten Kukuk <email@example.com>.
ypbind-mt Version 1.19 October 2004 ypbind(8)